76 lines
1.6 KiB
C
76 lines
1.6 KiB
C
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#pragma once
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#include <atomic>
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#include <memory>
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template<typename T>
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class LockFreeQueue {
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private:
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struct Node {
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std::atomic<T*> data{nullptr};
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std::atomic<Node*> next{nullptr};
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};
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std::atomic<Node*> head_{nullptr};
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std::atomic<Node*> tail_{nullptr};
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public:
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LockFreeQueue() {
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Node* dummy = new Node;
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head_.store(dummy);
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tail_.store(dummy);
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}
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~LockFreeQueue() {
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Node* current = head_.load();
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while (current != nullptr) {
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Node* next = current->next.load();
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T* data = current->data.load();
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if (data != nullptr) {
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delete data;
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}
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delete current;
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current = next;
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}
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head_.store(nullptr);
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tail_.store(nullptr);
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}
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void push(T item) {
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Node* new_node = new Node;
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T* data = new T(std::move(item));
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new_node->data.store(data);
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Node* prev_tail = tail_.exchange(new_node);
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prev_tail->next.store(new_node);
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}
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bool try_pop(T& result) {
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Node* head = head_.load();
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Node* next = head->next.load();
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if (next == nullptr) {
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return false;
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}
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T* data = next->data.load();
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if (data == nullptr) {
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return false;
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}
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result = *data;
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delete data;
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head_.store(next);
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delete head;
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return true;
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}
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bool empty() const {
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Node* head = head_.load();
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Node* next = head->next.load();
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return (next == nullptr);
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}
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};
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